A recent study has found that omega-3 fatty acids can significantly reduce symptoms of depression and anxiety in young mice subjected to stress, with the mice exhibiting both molecular and behavioral changes. This finding, published in Neurobiology of stressoffers hope for new treatments for adolescent depression in humans.
Major depressive disorder is a debilitating mental health problem that is increasingly affecting young adults around the world, particularly due to the COVID-19 pandemic.
While adults have several treatment options, adolescents often find these therapies ineffective or even harmful. The search for alternative treatments has led researchers to explore the potential benefits of omega-3 fatty acids, which are commonly found in fish oil and are known for their anti-inflammatory properties.
The study therefore aimed to understand whether omega-3s could counteract the effects of stress-induced depression in young mice. Stress is a known trigger for depression, and the researchers used ultrasound frequencies to simulate emotionally stressful conditions that led to depression-like behaviors in the mice.
The methodology involved exposing 40 one-month-old mice to alternating ultrasound frequencies for three weeks, mimicking negative (20 to 25 kilohertz) and neutral (25 to 45 kilohertz) emotional states. At the same time, the mice were fed either a diet with omega-3 supplements, containing eicosapentaenoic acid and docosahexaenoic acid, or a “dummy” supplement containing no omega-3 (a placebo).
The results were promising. Mice treated with omega-3 showed marked improvements in behavior, displaying fewer symptoms of anxiety and depression compared to those on a normal diet.
Specifically, the group of mice that received the placebo showed a reduced preference for consuming freely available sugar water. This indicated anhedonia (an inability to experience pleasure from activities that normally bring pleasure), which is a key symptom of depression.
Additionally, mice that consumed omega-3 showed fewer anxiety-related behaviors. For example, when placed in an empty square box, the mice were more adventurous and spent more time in the center of the “open field.”
Omega-3 intake also caused changes in brain, blood and liver metabolism, as well as a decrease in proinflammatory cytokines, suggesting a molecular basis for the behavioral improvements.
However, levels of the hormone cortisone, induced by ultrasound stress, remained high.
“This discrepancy suggests that while omega-3 may mitigate some inflammatory responses, it may not affect all stress-related hormonal pathways. [Omega-3 influences] “Several parameters that were not altered by stress, which independently appear to exert a protective effect,” the authors noted.
It is important to note that while these findings are encouraging, they do have limitations. The main concern is whether the results from a mouse model can be translated to humans.
The study, “Omega-3 alleviates molecular and behavioral changes in a mouse model of stress-induced juvenile depression“The New York Times” was written by Tatyana Strekalova, Daniel Radford-Smith, Isobel K. Dunstan, Anna Gorlova, Evgeniy Svirin, Elisaveta Sheveleva, Alisa Burova, Sergey Morozov, Aleksey Lyundup, Gregor Berger, Daniel C. Anthony and Susanne Walitza.
